1. Field of the Invention
The invention relates to sensor (camera) systems for automobile applications and more particularly to infrared (“IR”) sensor systems for automobile applications.
2. Description of the Known Art
Some modern automobiles include sensor systems, more particularly, IR sensor systems which are located under the hood of the vehicle, with the field of view of the sensor system pointing forwardly of the vehicle. Normally, the sensor system is used to acquire an image of the scenery in front of the automobile. This image will help the driver of the automobile to see, particularly in the case of relatively warm objects (such as pedestrians and large animals), in dark conditions. The image from the sensor system could also be processed to identify and mark objects that should be observed by the driver. Clearly, accurate readings are needed from the sensor system for such a system to function effectively.
Imaging or sensing systems using a camera may also be used to produce inputs for safety or vehicle control systems which may not present any image to the driver. Examples of such systems include obstacle detection systems to trigger vehicle occupant or pedestrian safety systems, closing velocity or range sensing for engine shutdown control, parking assist systems, lane departure systems and vehicle blind spot detection systems.
Sensor systems generally include a sensor assembly containing a detector with multiple pixel array. Additionally, an optical arrangement is utilized such that scene energy received by the optical arrangement is directed to the sensor assembly. In order for scene energy to be properly directed from the optical arrangement to the sensor assembly, the sensor assembly must be carefully positioned so as to properly align the scene on the sensor array and with the optical center and maximize the amount of energy received from the optical arrangement during assembly. Prior art solutions have generally required that the sensor assembly be carefully aligned. This alignment is generally achieved by first determining the location of the center pixel of the sensor assembly. Thereafter, the sensor assembly is aligned with the aid of an alignment spring, gasket, retainer, and fasteners so that the center pixel is located such that it is at the center of the image directed by the optical arrangement. This system and method for aligning the sensor assembly is costly and is fairly difficult to consistently achieve. Therefore, there is a need for an improved system for aligning the sensor assembly.